1. Field of the Invention
This invention relates generally to fiber optic terminations and is concerned more particularly with method and means for cleaving an optical fiber element of a fiber optic cable.
2. Discussion of the Prior Art
A fiber optic cable of the single conduit type comprises a filamentary optical fiber made of flexible light-pipe material, such as glass, for example, and provided with a buffer coating of flexible material, such as opaque plastic material, for example. The coated optical fiber may be laid axially with a stiffening wire of flexible tension-absorbent material, such as steel, for example; and the combination encircled by a protective jacket of flexible material, such as a rugged plastic material, for example. Thus, the single conduit fiber optic cable resembles, in appearance, a single conductor electrical cable having an insulation coated wire and an uninsulated ground wire encircled by a protective jacket of flexible material.
This similarity of the single conduit fiber optic cable to the single conductor electrical cable also may extend to its use and installation. For example, the optical fiber element of the fiber optic cable may be employed for transmitting informational data from a source to a receptor device in the form of light pulses, just as the insulation coated wire of the electrical cable may be employed for conducting the informational data by means of electrical pulses. Also, the single conduit fiber optic cable may have its end portions secured to respective connectors for coupling the optical fiber element to the source and to the receptor device to transmit light energy efficiently from the source to the fiber optic cable and from the fiber optic cable to the receptor device. Furthermore, when the source is located from the receptor device a distance greater than the length of one fiber optic cable, a coupler device may be provided for coupling a connector at one end of the fiber optic cable to a connector at an adjacent end of another fiber optic cable in a manner which promotes the efficient transmission of light energy from one to the other of the fiber optic cables.
To minimize losses in light energy entering and leaving the fiber optic cable, the terminal end surfaces of the optical fiber generally are made mirror-flat, as by polishing, for example, and are disposed substantially perpendicular to the axis of the fiber. Also, in order to maintain these end surfaces mirror-flat and perpendicular, as described, the terminal end surfaces of the optical fiber are not disposed in butting engagement with a connecting component but, instead, are spaced therefrom a predetermined distance, such as one to ten thousandths of an inch, for example. Consequently, after the terminal end surfaces of the optical fiber have been prepared, as described, the connectors generally are mounted on respective end portions of the fiber optic cable and secured to the optical fiber, as by bonding, for example. As a result, the terminal end surfaces of the optical fiber are fixed in relation to preselected portions, such as positive-stop shoulders, for example, of the connectors which ensure that the terminal end surfaces will be spaced the predetermined distances from the connecting components.
Since the polishing process for preparing the terminal end surfaces of the optical fiber does not lend itself very readily to use in the field, there has been developed in the prior art a number of field tools for cleaving the glass optical fiber in a plane transverse to the axis of the fiber. However, these prior art cleaving tools generally are designed for cleaving the optical fiber before securing the connector, as by bonding, for example, to the cleaved end portion of the optical fiber. Consequently, it is necessary to secure the connector, in the field, to the cleaved end portion of the optical fiber such that the resulting terminal end surface is fixed a predetermined distance from a preselected portion of the connector. Also, some of the prior art cleaving tools cause the glass optical fiber to break in a transverse plane by sharply bending the fiber or unduly stressing the glass material. As a result, cracking or chipping may occur subsequently at the cleaved end portion of the optical fiber and cause prohibitive losses in light energy entering or leaving the fiber optic cable.